Admitting a chained ACDC with non-resolved schemas is prone to escrow timeout

[iFergal]

The Granter in KERIA will stream all artifacts (KELs, registry events, chained ACDCs and their artifacts recursively, etc) to a disclosee.

The disclosee can receive the credential by admitting, which will parse the embedded ACDC. The other artifacts necessary will have already been parsed so long as all schemas are resolved.

Lets assume schemas are dynamically discovered once the user comes online on their edge device (e.g. Veridian Wallet). If the user comes online over an hour later (escrow timeout for credential parsing), this poses an issue:

• Chained ACDCs will not have parsed due to a missing schema
• Leaf ACDC will not parse due to missing chains

I might be a good idea for KERIA to be able to handle this automatically and discover schemas when receiving a grant.

[kentbull]

Options we discussed:

• use schema section message (ACDC 2.0) to send the schema as a part of sharing an ACDC. This is one and done and does not require OOBI resolution of a schema URL.
• pushing it (the schema) with an unsolicited reply message along with a credential presentation.
• use the query/reply process
• use well-known OOBIs from published locations for a given ecosystem